No Till Notes: 'Observations, Part 2'

Last week, I discussed how we approach fertilizing our winter wheat crop following field peas in our winter wheat, corn, field pea and then back to winter wheat crop rotation on our continuous no-till dry land acres. We have been using this rotation for the past nine years on our farm and we’re starting to see some long term effects from this rotation.

One observation is cheat grass working its way into a few fields within this rotation. Cheat grass has always been a problem in winter wheat production in our region. Throughout my farming career, we have tried plowing, disking, spraying herbicides, and various crop rotations trying to control cheat grass in our winter wheat fields. I wish I had all the money I’ve spent over the years trying to control cheat grass in winter wheat production!

I visited with another producer last week who has observed the same problem in his winter wheat fields where he has been raising winter wheat following his field pea production. My observation in this rotation is we are controlling the cheat grass prior to field pea emergence with our pre-emergence herbicide program.

The problem I have noticed is we seem to have a second flush of spring cheat grass emergence after the field peas have germinated and begun growing. This second flush of cheat grass emergence in the growing field peas on some of our fields has led to a cheat grass problem in our winter wheat.

As we scouted our winter wheat fields this spring there was cheat grass that was just beginning to emerge after the winter wheat had broken dormancy and begun to grow. Our only option was to spray these fields with herbicide to control cheat grass in winter wheat.

Fortunately, there have been some good herbicides developed that do a fine job of controlling cheat grass in winter wheat. The herbicide we used also has very limited restrictions regarding when we can plant other crops we produce in our rotation. Another option to controlling the cheat grass in the future would be to use a grass herbicide with our pre emergence herbicide program in the field peas. This would require treating all our field pea acres with a grass herbicide.

Yet a different option would be to scout the field pea fields after the field peas have emerged and treat the fields, or areas of the fields where we find spring cheat grass germinating. This is the option we have chosen as most fields don’t seem to have a cheat grass problem, or the field borders can be sprayed with a post emergence herbicide to control any cheat grass that emerges.

Lengthening our crop rotation and possibly adding another summer crop in the rotation to help control the cheat grass could also be an option. Changing the crop rotation would also have some ramifications such as managing and marketing another crop. If we choose to put another summer crop in the rotation we would also be more dependent on mid to late summer rains to produce a profitable crop. Some years a summer rain can be hard to come by.

I would encourage field pea producers to scout your fields and look for any problems that may arise. Mother Nature always has a way of adapting to any crop rotation and eventually throwing a challenge into the rotation.